This invention relates to the technical field of color image recording apparatus, more particularly, those which are used with advantage in the creation of (color) proofs in the printing field.
With the recent advances in digital technology, it is expected in the printing industry that the technology is utilized to verify the quality of copy at an early stage of the process starting with its input and ending with the printing (outputting) of the final copy so that the number of required corrections is reduced to achieve higher productivity. The quality verification employs a hard copy called "proof" or "color proof" which has the same image recorded as in the actual print. Hence, the proof is required to have a high degree of similarity to the actual print (of final copy) in terms of not only graphics pattern but also color and/or density.
The proofs are typically created by color image recording apparatus (color proofing apparatus) employing various techniques such as electrophotography, thermal transfer by sublimation, thermal transfer by fusion and ink jet printing. However, the conventional color proofing apparatus employing these methods are not completely satisfactory in performance for the following reasons and need substantial improvements.
Most of the color proofs for printing are of A4 or A3 size but larger sizes A2 and A1 are also available. With the conventional color proofing apparatus, the speed of creating larger proofs is quite slow, i.e. about 20 minutes with the A2 size and as long as about 40 minutes with the A1 size, which means very low efficiency.
As already mentioned, the color proof is required to have a degree of high similarity to the actual print and the color proofing apparatus must be capable of outputting a print-quality color proof with satisfactory color reproduction in a consistent manner.
Therefore, the image quality of the color proof is required to be comparable to that of the final print in various aspects including color/density resolution, image gradation and granularity. However, it is difficult for the conventional color proofing apparatus to meet all of these requirements and yet ensure high productivity. It goes without saying that neither color proofing apparatus which satisfy more rigorous requirements such as similarity in color to the actual print and consistent color reproduction nor a technology that can put the apparatus into commercial use have yet been realized.